Electrical and optical properties of CuAlSe2 grown by iodine chemical vapor transport

Abstract

Resistivities, carrier concentrations, optical absorption, and photoluminescences of undoped and Cd,Zn-doped CuAlSe2 single crystals grown by chemical vapor transport were studied. The electrical and optical properties were almost unchanged after annealing under Se pressure. However, the resistivity increased about seven orders of magnitude after annealing in vacuum. The resistivity also increased by Cd or Zn doping. The samples showed p-type conduction even when Cd or Zn was doped. An acceptor ionization energy of about 65 meV was obtained. The mobility showed the dominance of lattice scattering for temperatures between 80 and 200 K. Two independent, broad, red luminescences having their own excitation energies were observed at relatively low temperature. We have proposed the configuration coordinate model for this characteristic emission. The emission can be interpreted as radiative transitions from a deep center to the respective A or C valence bands, accompanied by a lattice relaxation.

Growth and characterization of CuAlSe2(112)/GaAs(100) heteroepitaxial layers grown by hot wall epitaxy method

“…This is coincided with the mobility result obtained by Chichibu et al [18]. For the CuAlSe 2 bulk grown by iodine chemical vapor transport, they reported that the mobility of T À3/2 varies approximately between 120 and 300 K. But, the mobility values are low by approximately one order in comparison with our values [18]. They explained that the cause of the low values of the Hall mobility might be due to an electrical compensation by the native defects or the extrinsic impurities, because Si acts a donor when it replaces the Al site.…”

“…This indicates that scattering at the high-temperature range is mainly due to the acoustic mode of lattice vibration through a deformation potential and scattering at low-temperature range is most pronounced due to the impurity effect [17]. This is coincided with the mobility result obtained by Chichibu et al [18]. For the CuAlSe 2 bulk grown by iodine chemical vapor transport, they reported that the mobility of T À3/2 varies approximately between 120 and 300 K. But, the mobility values are low by approximately one order in comparison with our values [18].…”

“…This peak is associated to the E x . The observation of the E x from the CuAlSe 2 is very difficult because of the difficulty in growing single crystals of high quality [18,19]. The CuAlSe 2 single crystal grown by the traveling heater method was observed only at 2.6 eV [20].…”

Structural phase transition, elastic properties and electronic properties of chalcopyrite CuAlX2 (X=S, Se, Te)

“…CuAlX 2 (X = S, Se, Te) belongs to the family of chalcopyrites, in experiments several studies have been carried [15,16] on the electronic, electrical, and optical properties of CuAlX 2 (X = S, Se, Te) at ambient pressures. However, high-pressure studies of these chalcopyrite semiconductors have attracted considerable attention due to their phase transition and electronic properties [17][18][19][20][21][22].…”

Growth and characterization of CuFeS2 thin films

“…It has been shown that while chalcopyrite with band gap between 1 and 1.4 eV such as CIS and CIGS can exhibit either n-or p-type conductivity by varying their composition [2], it is far more difficult to achieve n-type chalcopyrite with broader band gap such as CGS and CuAlSe 2 [12][13][14]. To our knowledge, up to now, no information is available in the case of small band gap chalcopyrite thin films.…”